The bankruptcy filing by the owner of Sparrows Point casts yet another cloud over the future of steel-making there, but spokespeople for RG Steel and the Maryland Department of the Environment both say it should have no effect on the cleanup of longstanding toxic contamination there.

The company has continued cleanup work begun in 2010 by the mill's previous owner, Severstal North America, pumping and treating contaminated ground water to fulfill the terms of a consent decree with federal and state regulators that was agreed to in 1997 by the mill's original owner, Bethlehem Steel, which later filed for bankruptcy and sold the complex, beginning a series of handovers of the troubled facility.

"The obligations of the consent decree remain in effect regardless of the bankruptcy," Jay Apperson, spokesman for the state environment department, said in an email. He noted that RG Steel earlier this month had submitted a plan required by a federal court order for investigating the extent of toxic contamination in sediments just offshore in Bear Creek, a tributary of the Patapsco River.

It's unclear if RG Steel's move to seek Chapter 11 protection from its creditors will complicate other litigation over environmental issues around Sparrows Point. The Chesapeake Bay Foundation had sued RG Steel alleging polluted storm-water was washing off the complex that needed to be curbed. Foundation lawyer Jon Mueller said he saw no bar to the case, since the Annapolis-based environmental group is not seeking any money damages, but instead wants to make the company get environmental permits requiring it to control its runoff better.

A prospective class-action lawsuit by Dundalk, Turners Station and other Sparrows Point area residents, though, may have a tougher time. Residents have been meeting with lawyers for a few years now, discussing whether to seek damages for the alleged harm to their health and property from decades of pollution by the mill. No case has been filed.